Inside Health

NEWS ANALYSIS; Advance on Stem Cells Equalizes Debate

By SHERYL GAY STOLBERG

Published: November 21, 2007

It has been more than six years since President Bush, in the first major televised address of his presidency, drew a stark moral line against the destruction of human embryos in medical research.

Since then, he has steadfastly maintained that scientists would come up with an alternative method of developing embryonic stem cells, one that did not involve killing embryos.

Critics were skeptical. But now that scientists in Japan and Wisconsin have apparently achieved what Mr. Bush envisioned, the White House is saying, ''I told you so.''

Conservative Republican presidential hopefuls like former Gov. Mitt Romney of Massachusetts are breathing a sigh of relief. And opponents of embryonic stem cell research are congratulating themselves.

The discovery that skin cells can be reprogrammed to mimic embryonic stem cells is likely to transform the sticky political debate over the science, a debate that has pitted Mr. Bush against two-thirds of the American public including prominent Republicans like Nancy Reagan and has even helped decide some elections.

The findings have put people on both sides of the stem cell divide on nearly equal political footing. Each side can now say it has fruitful research to pursue.

Each side can even lay claim to the same scientists. The author of the new skin cell studies is James A. Thomson, the University of Wisconsin researcher who extracted stem cells from human embryos in the first place.

Perhaps no one outside the world of science is as acutely aware of this as Mr. Bush. The president and his aides have been quietly monitoring the Wisconsin experiments for months, receiving briefings from Elias A. Zerhouni, director of the National Institutes of Health.

On Tuesday, senior aides to Mr. Bush said he drove the experiments by holding his moral ground.

''This is very much in accord with the president's vision from the get-go,'' said Karl Zinsmeister, a domestic policy adviser to Mr. Bush who kept the president apprised of the work. ''I don't think there's any doubt that the president's drawing of lines on cloning and embryo use was a positive factor in making this come to fruition.''

Mr. Bush's critics say he should not be so quick to take credit. They note that the reprogramming method has some kinks to be worked out and say the research would never have proceeded without the initial embryo experiments. The critics say that far from encouraging research, Mr. Bush has stood in its way.

In 2001, in a compromise aimed at discouraging the destruction of embryos, Mr. Bush told federal researchers that they could work just on those stem cell lines, or colonies, already in existence. He has twice vetoed bills to ease those restrictions.

''I really don't think anybody ought to take credit in light of the six-year delay we've had,'' said Senator Arlen Specter of Pennsylvania, the lead Republican sponsor of the bill that Mr. Bush vetoed in July 2006. ''My own view is that science ought to be unfettered and that every possible alternative ought to be explored.''

''You've got a life-and-death situation here,'' Mr. Specter continued, ''and if we can find something which is certifiably equivalent to embryonic stem cells, fine. But we are not there yet.''

Embryonic stem cells are attractive to scientists because they have the potential to grow into any cell or tissue in the body and could, theoretically, be used to treat many ailments. Opponents, including Christian conservatives, say it is immoral to destroy embryos to obtain cells.

Early in the controversy, opponents, including Mr. Bush, often said they supported studies using so-called adult stem cells that involve cells extracted from blood and bone marrow. But those cells have more limited potential than embryonic stem cells, and proponents of embryo experiments said it was like comparing apples to oranges. The reprogrammed skin cells, by contrast, appear to hold the same properties as embryonic stem cells, more an apples-to-apples comparison.

''We now have a situation where, ironically, despite an inability to get political consensus, the science has presented opportunities for a variety of moral views to have an outlet,'' Arthur L. Caplan, director of the Center for Bioethics at the University of Pennsylvania, said. ''Proponents can no longer say that there aren't any real options.''

The debate has even been a factor in some elections like the Missouri Senate race last year. In that contest, Claire McCaskill, a Democrat, unseated Jim Talent, a Republican who opposed the research. The race drew national attention after the actor Michael J. Fox, who has Parkinson's disease and has been a vocal advocate for stem cell studies, made a commercial for Ms. McCaskill.

The new findings could defuse the issue in the 2008 campaign, or at least that is the hope of candidates like Mr. Romney.

''This will bolster the arguments of folks like Governor Romney, who look at alternative types of research that they believe are more promising and don't have those same ethical dilemmas,'' Kevin Madden, Mr. Romney's press secretary, said. At the same time, scientists may well begin pursuing reprogramming with vigor, if only because it is easier to obtain federal money for it, said Robert P. George, a professor of jurisprudence at Princeton who is on the president's Council on Bioethics and opposes embryo experiments.

''I'm sure in their ideal world, we would be pursuing all methods, and that includes embryo-destructive methods,'' Professor George said. ''Those who want to continue to fight on this will no doubt continue. But the ranks are going to be reduced.''

That is not to say advocates for embryonic stem cell studies plan to give up. Mr. Specter and other supporters of the bill to lift Mr. Bush's rules say they intend to continue to try to turn that bill into law, if not in this administration, then in the next one.

''None of this feels like it should be one versus the other,'' said Representative Diana DeGette, the Colorado Democrat who is sponsoring the bill in the House. ''That's the politicization of science.''